`cos^-1(cos( (8pi)/3))`has the value equal to -

cos (cos^-1 cos((8pi)/7) +tan^-1 tan(8pi/7)) has the value equal to -

5. if the expression cos^2(pi/11)+cos^2((2pi)/11)+cos^2((3pi)/11)+cos^2((4pi)/11)+cos^2((5pi)/11) has the value equal to p/q in it lowest from ; then find (p+q)

Let alpha = tan^-1 (1/2)+tan^-1(1/3) , beta=cos^-1(2/3)+cos^-1(sqrt5/3) , gamma=sin^-1(sin((2pi)/3))+1/2cos^-1(cos((2pi)/3)) The value of cos(alpha+beta+gamma) is equal to (A) cos((5pi)/12) (B) cos ((7pi)/12) (C) -cos(pi/12) (D) -cos ((7pi)/12)

4. cos^-1(cos((7pi)/4)) is equals to:

cos^(-1)(cos((7pi)/6)) is equal to (A) (7pi)/6 (B) (5pi)/6 (C) pi/3 (D) pi/6

96 sqrt3 sin(pi/48) cos(pi/48) cos(pi/24) cos(pi/12) cos(pi/6) has the value

The value of cos[1/2cos^(-1)(cos(-(14pi)/5))]\ is/are a. cos(-(7pi)/5) b. sin(pi/(10)) c. cos((2pi)/5)\ d. -cos((3pi)/5)

let cos(pi/7),cos((3pi)/7),cos((5pi)/7), the roots of equation 8x^3 - 4x^2 - 4x +1=0 then the value of sin(pi/14),sin((3pi)/14),sin((5pi)/14)

Find the values of cos pi/8

cos(pi/14)+cos((3pi)/14)+cos((5pi)/14)=kcot(pi/14) then k is equal to